Welded plate heat exchangers are commonly made of flat, parallel plates sandwiched together and welded between cover panels. Two fluids, one relatively hot and the other relatively cold, are passed between alternate plates for heat transfer. Plate heat exchangers require less space than shell and tube heat exchangers, and transfer heat at a much higher rate.
The heat exchanger of this invention is made of two sets of plate assemblies. The plate assemblies of the first set are arranged with the plate assemblies of the second set in a stacked relationship, with the plate assemblies of the first and second sets respectively interleaved or alternated with one another. Each plate assembly has first and second plates which define a space for the flow of fluid. The plate assemblies are in heat transfer contact with one another and provision is made for venting between the plate assemblies to allow for possible leaks but without contamination of one fluid by the other. Preferably, at least one of the plates of each plate assembly have raised dimples to establish the spaced relationship between the plates and also to produce turbulence in the flow of fluid.
The plates of each plate assembly have end portions which cooperate to provide an inlet and an outlet for fluid. The end portions of at least one of these plates is offset to enlarge the inlet and outlet openings. The enlargement of the inlet and outlet openings substantially reduces pressure drop and pumping cost.
Preferably, all of the inlet openings for the plate assemblies of each set communicate with a manifold for the introduction of fluid and all of the outlet openings for the plate assemblies of each set communicate with a manifold for the withdrawal of fluid.
The heat exchanger of this invention is preferably of all welded construction, is compact, lightweight, low in cost, operates at low fluid volume, has a high pressure rating, high performance and high efficiency.
It is an object of this invention to provide a plate heat exchanger having some or all of the above features.
Another object is to provide a plate heat exchanger which is of relatively simple construction, rugged and durable in use, and easy to manufacture and assemble.
Another unique feature of this invention is using dimples of varying height to achieve less pressure drop, when required, while still maintaining turbulence for good heat transfer.
Other objects, features and advantages of the invention will become more apparent as the following description proceeds, especially when considered with the accompanying drawings.